function plot_fem_argyris

v1 = [2,0]; v2 = [0,2]; v3 = [-1,0];
v13 = (v1+v3)/2;v12 = (v1+v2)/2;v23 = (v2+v3)/2;

figure('Position',[100,100,200,150]);
plot([v1(1),v2(1),v3(1),v1(1)],[v1(2),v2(2),v3(2),v1(2)],'k');hold on;
plot([v1(1),v2(1),v3(1)],[v1(2),v2(2),v3(2)],'k.');
text(v1(1)+0.2,v1(2),'v_1','FontSize',10);
text(v2(1)+0.2,v2(2)+0.05,'v_2','FontSize',10);
text(v3(1)-0.45,v3(2)-0.05,'v_3','FontSize',10);
text(v23(1)+0.1,v23(2),'v_{23}','FontSize',10);
text(v13(1),v13(2)+0.1,'v_{13}','FontSize',10);
text(v12(1)-0.3,v12(2),'v_{12}','FontSize',10);
theta = 0:0.01:2*pi;
r1 = 0.1; r2 = 0.2;
x1 = r1*cos(theta); y1 = r1*sin(theta);
x2 = r2*cos(theta); y2 = r2*sin(theta);
plot(x1+v1(1),y1+v1(2),'k','Linewidth',2);plot(x2+v1(1),y2+v1(2),'k','Linewidth',2);
plot(x1+v2(1),y1+v2(2),'k','Linewidth',2);plot(x2+v2(1),y2+v2(2),'k','Linewidth',2);
plot(x1+v3(1),y1+v3(2),'k','Linewidth',2);plot(x2+v3(1),y2+v3(2),'k','Linewidth',2);

% The middle dof
% plot(0.5*[v1(1)+v2(1),v2(1)+v3(1),v3(1)+v1(1)],0.5*[v1(2)+v2(2),v2(2)+v3(2),v3(2)+v1(2)],'k.');

len = 0.3;
% The normal derivatives on the middle point
dir = [v1(2) - v3(2), v3(1) - v1(1)];
dir = dir/norm(dir,2);
quiver(v13(1),v13(2), len*dir(1), len*dir(2),'Color','black','Linewidth',3);
%line([v13(1),v13(1) + len*dir(1)],[v13(2),v13(2) + len*dir(2)],'Color','black');

dir = [v2(2) - v1(2), v1(1) - v2(1)];
dir = dir/norm(dir,2);
quiver(v12(1),v12(2),len*dir(1),len*dir(2),'Color','black','Linewidth',3);
%line([v12(1),v12(1) + len*dir(1)],[v12(2),v12(2) + len*dir(2)],'Color','black');

dir = [v3(2) - v2(2), v2(1) - v3(1)];
dir = dir/norm(dir,2);
quiver(v23(1),v23(2),len*dir(1),len*dir(2),'Color','black','Linewidth',3);
%line([v23(1),v23(1) + len*dir(1)],[v23(2),v23(2) + len*dir(2)],'Color','black');

axis equal;axis([-1.3 2.3 -0.3 2.3]);axis off;
% out put text
%text(1.5,1.8,'P_K=P_5;dim P_K=21;');
%text(1.5,1.5,'\Sigma_K=\{p(v_i),\frac{1}{2};');
%text(2.5,1.2,'p(v_{ij})');
%text(2.5,0.9,'p(v_{ij}),i<j,i=1,2,3\}');